This article interests me for two reasons -- one, it addresses animal behavior and got me thinking about octopuses, and two, it has been a long-time interest of mine to find a way to require less sleep for myself. Imagine all the things I could accomplish if I could be "productive" during the hours I usually spend asleep! (Hey, managing this site takes time you know... And another thing... )

Anyway... the article above addresses the non-sleep behavior of certain animals -- for example, it remarks on how dolphins must stay awake at all hours, to the extent they are aware enough to return to the surface to breathe.

So, all this leads to my question: do we know anything about how/whether octopuses sleep? Would be interested in hearing what anyone here knows about this.

O. bimaculoides

There was a programme (Horizon) in the UK on BBC2 16/1/03 on sleep disorders. Humans need a chemical produced by the brain called arexin (spelling?). This is needed to keep us awake, it could be synthesized artificially, we could in theory take a tablet and stay awake permantly!

Just for the record my Octopus appear to sleep, if only lightly. The retina seems to close up, and sometimes the skin around the eye contracts. There is also a change in colour pattern, normally go pale. They are awaken by movement, or the chance of being fed.
Well I think there sleeping, can't think what else it could be. I'm trying to get some pics, but as soon as I move they wake up.

Colossal Squid

Ya know after Hermin eats, he curls up whether in his barnicle or in some odd place, I swear he's sleeping it off! I have noticed his eyes seem to close a little. When he's aware of us the "eye" is watching! but when he's resting, he seems very unaware of anything.

Pygmy Octopus

A few years ago, I read about an experiment in which mice, through prodding or drugs, were kept continuously awake. They all died within a fairly short time range, less than two weeks if my memory serves me. Also, I'm fairly certain that dolphins rest one hemisphere of their brain at a time.
Brandon

TONMO Supporter

Id say that the cuttlefish i have kept were more obviously sleeping than the octopuses. I suppose this is easier to see on the cuttles cuz they would lie at the front of the tank. Sometimes you could walk up slowly and they'd still be unaware of you, but if you tap the glass gently they immediately woke up... you could then see the 'W' shaped pupil open wide up!

In my experiences of keeping lots of fish they also sleep quite heavily. A large fish I had which is called an Oscar used to sleep on its side and while in Trinidad I was catching Blue Acaras by hand as they slept in the shallow parts of the streams.

O. bimaculoides

Attached is a photo of one of my Octo's eyes when I believe it to be asleep
It's colour is very light and is generally won't respond to normal stimuli, as you can see it's pupil is very small and the skin around it's eye is contracted.
J.Scott

O. bimaculoides

The camera I normally use is a Fuji FinePix F601Z.
I normally use it in manual mode where I can set shutter speed and aperture size. Using a the slow shutter is great in low light conditons, if the will subject stay still. The 3X optical 6X digital zoom is pretty handy too.
My old camera was auto focus only, I found best results were obtained with the flash off and holding the camera very close to the glass. My avatar was taken with this camera.
Both my Octos are in bedrooom / home office. This means I'm normally in the right place at the right time to capture their behaviour.